Reminders lets you organize your life in to-do lists — complete with due dates and locations. Say you need to remember to pick up milk during your next grocery trip. Since Reminders can be location based, you’ll get an alert as soon as you pull into the supermarket parking lot. http://www.apple.com/ios/features.html

Mariette can also do the job but with improvements. It can search for address on the map, not only from contact list. want to see more ? .

Some iPad users have experienced a problem editing locations. the problem is related to the control that changes the radius of the location. The problem is located and solved an update will come soon, it will be v1.3.